'I'm really looking forward to Glastonbury,' says U2 bassist Adam Clayton. 'It's been a long time coming.' A year in fact, with the band moving last year's headline appearance back 12 months after Bono put his back out. They're currently on the closing leg of what is now the highest grossing tour of all time, projected to have taken around $700m when it ends in July. And despite having been together for 35 years, U2 have never played the festival before. Guitarist Edge might have made a quick guest appearance with Muse last year but only Clayton can boast of any proper experience of Worthy Farm. 'Many years ago the Hothouse Flowers and the Waterboys were on the bill and I tagged along and had a good time,' he says. 'I stayed in a tent and remember being woken up on Saturday morning by the sound of whoever was opening the main stage.'

MY TEENAGE REBEL YEARS

'Won't Get Fooled Again', the Who (1971)

When I was about 13 or 14 years old, music became something that kept my dreams alive rather than something that was just on in the background. My parents were English but had moved to Ireland and put me into a prep school at eight, then a boarding school at 13. I never liked that type of schooling: all the authority seemed antiquated and not what education should be about. So my school life was a litany of minor offences of individuality. I was never involved in bullying or stealing, I just had a problem with every rule that affected who I was. I grew my hair, wore hippy clothes, anything to stand out from the crowd.

I was frequently put in detention. One of the favourite punishments of my housemaster was to make me get up an hour early, at 6.30am, and be at his door by quarter to seven, just to prove that I was up. At least he wasn't beating boys with a cane.

I'm not sure whether the Who inspired my resistance to the life that was being planned for me, or whether the seeds of the rebellion were already in my DNA, and this record struck a chord. It was probably the latter.

MY SUMMER IN PAKISTAN AND AFGHANISTAN

'Roots, Rock, Reggae', Bob Marley (1976)

The school, and my parents, gave up on me after my O-levels. I was asked to leave, and would be going to a comprehensive the following term. So I didn't want to be at home that summer because the mood was awful. A friend's father was the Australian ambassador to Pakistan and Afghanistan, and he invited me to hang out over there instead. He told me you could get "jazz tobacco" and that there were large numbers of American girls who were very bored. Which was all the encouragement I needed.

That summer was a wild and mind-expanding time, two months of sex and drugs and rock'n'roll that determined that whatever I would do in future, it had to be creative. There was a lot of incense, patchouli oil and smoking pipes with big lumps of black stuff in them, all the things you associate with the 70s and the hippy trail. I bought an Afghan coat, heard Bob Marley for the first time and was drawn to the freedom in his music.

LEARNING TO PLAY THE BASS

'Hanging Around', the Stranglers (1977)

The comprehensive I went to in Dublin was where I met Edge, Bono and Larry. I much preferred it. It came with the freedom that I'd been deprived of, including the length of my hair and the clothes I wore. Punk was beginning and I connected with it immediately. Suddenly there was a line between people who listened to Led Zeppelin and people who listened to punk and I knew which side I was on. And to put it in context, our generation was facing an uncertain future. We were down to petrol rationing and a three-day week. Punk seemed like a movement that could question authority, although it doesn't seem quite so radical now. I remember hearing the bass on "Hanging Around" and immediately knowing it was going to be the instrument for me. Punk meant you didn't necessarily have to know how to play that well – you could do what you want. And in the hands of the Stranglers' Jean-Jacques Burnel, the bass was a weapon of mass destruction. It was the aggressiveness of the way he played that I picked up on.

Not too long after this, Larry [Mullen Jr, U2 drummer] put a notice on the school notice board, looking for anyone interested in forming a band. It took a few months to find our voice and in the beginning it wasn't happening fast enough. Paul Weller was making records at 18 and we wanted that as well.

DISCOVERING AMERICA

'What's Going On', Marvin Gaye (1971)

By 1984 we were making Unforgettable Fire with Brian Eno and Daniel Lanois, and moving away from a punk-based sound. Danny introduced me to a lot of rhythmic American music that I'd missed, soul and dance music that we had not been exposed to in Ireland. He made me listen to a lot of Motown, particularly tracks that featured the bass player James Jamerson, who was in the label's house band the Funk Brothers, and who plays on this track. I learned that the bass could be seductive and subtle, and James Jamerson has been with me ever since. And it started a romance with certain aspects of American culture – this was music that had a connection with civil rights – although for me the relationship was always more instinctive than intellectual, and came through these kind of musicians.

THE RECORD THAT HELPED ME LOOSEN UP

'Back to Life (However Do You Want Me)', Soul II Soul (1989)

By the end of 80s we were coming off the Joshua Tree and Rattle and Hum albums, which were enormous for us – we were on the cover of Time magazine. When you become that popular in such a short period, it can be hard to know where the ground is. You can get pretty out of touch. So as a band we slipped and slid all over the place. And we loosened up. We wanted to, because we were fed up with being the stoic men in the desert of those albums.

We'd lived in LA while were making Rattle and Hum, and had begun to hear a lot of rap, especially NWA, who were on the same label as us. And what was happening in the UK was Stone Roses, Happy Mondays and a lot of clubby stuff like Soul II Soul. We were aware the 90s were starting to happen, and we knew that these were the directions we wanted to go. There were a couple of nights I went to Ministry of Sound in London, and a few places in Paris, I can't remember exactly where. I wasn't going out nightly, because I was always travelling with the band, but I was hanging out with people who were, and would end up back at their houses until the early hours, discovering artists like Leftfield. And, of course, in the end the 90s proved to be a fantastic time for U2.